1. Field of the Invention
The present invention relates to a LED lamp employing a high-intensity light emitting diode (LED) as a light source. More particularly, the invention relates to a function of life time preannouncement of LED and notifying replacement timing thereof.
2. Description of the Related Art
As high-intensity blue LED has been put into practice, a LED lamp aggregatingly mounting red, green and blue color LEDs and driven by commercial alternating power source as general lighting equipment, has been in a stage of practical use. In comparison with a filament lamp or fluorescent lamp, LED lamps demonstrate a lot of advantages. Therefore, LED lamps will be spread significantly.
While the LED lamp has much longer life time than the filament lamp and fluorescent lamp, it still has a life time. Considering family use of the LED lamp, or use of the LED lamp as lighting equipment of a public space, such as an office, station or the like, the LED lamp is not well-seasoned as compared with the filament lamp or fluorescent lamp. Therefore,it should be difficult for general consumer to see the replacement timing of end of the life time of the LED lamp. Even though the LED lamp has quite long life time, it should be apparently and practically convenient to forecast replacement timing individually to notify to the manager.
The present invention has been worked out in view of the necessity as set forth above. It is therefore an object of the present invention to integrally build-in a function for preannouncement end of life time in a LED lamp per se and to realize the LED lamp having such function with simple construction and at low cost.
According to one aspect of the present invention, a LED lamp system comprises:
an alternating current power source connecting portion for receiving an alternating current;
a power source converting portion for receiving the alternating current and rectifying the received alternating current for generating a direct current power;
LED group consisted of a plurality of LEDs and received a direct current power output from the power source converting portion, the LED group having a life time preannouncement portion for integrating power supply period for issuing preannouncement indicative of approaching to the end of the life,
the life time preannouncement portion including:
counting means for measuring the power supply period on the basis of a frequency of the alternating power source,
integrating means for integrating the power supply period measured by the counting means and storing the integrated value in a non-volatile memory, and
power supply mode control means for controlling illumination of LEDs at different modes including a normal lighting mode, the power supply mode control means being responsive to an integrated value of the integrating means in excess of a predetermined criterion to operate in a predetermined life time preannouncement mode.
The power supply mode control means may check the integrated value stored in the non-volatile memory upon initiation of power supply so that the LED group is operated in the life time preannouncement mode for a predetermined period and in the normal lighting mode when the integrated value is in excess of the criterion.
The power supply mode control means may be set a plurality of criteria corresponding to a plurality of life time preannouncement levels for a plurality of mutually distinct preannouncement modes.
The LED lamp system may include a plurality of LED groups, each of which is consisted of a large number of LEDs of a color distinct from that of LEDs in other LED groups, and the power supply mode control means controls power supply modes of each color of LEDs.
The LED lamp system may further comprise light adjusting means for variably controlling illumination color of the LED groups by operating the power supply mode control means on the basis of an adjustment signal for illumination color and light amount applied externally.